Exam Prep for General Chemistry | Channels for Pearson+

Skip to main content

My Courses

AI Tools Channels Home

6. Chemical Quantities & Aqueous Reactions - Part 3 of 3

6. Chemical Quantities & Aqueous Reactions - Part 3 of 3

6. Chemical Quantities & Aqueous Reactions / Balancing Redox Reactions: Acidic Solutions / Problem 6

A 0.350 g sample of a certain semimetal M heated in air yielded the matching oxide M₂O₃. The reaction needed 7.67 mL of 0.125 M Cr₂O₇²⁻when the oxide was dissolved in aqueous acid and titrated with K₂Cr₂O₇. The unbalanced equation for the titration is H₃MO₃(aq) + Cr₂O₇²⁻(aq) → H₃MO₄(aq) + Cr³⁺(aq) (in acid).
How many moles of semimetal were present in the initial 0.350 g sample and how many moles of oxide were formed?

A

9.59×10⁻⁴ mol M
4.79×10⁻⁴ mol M₂O₃

B

1.44×10⁻³ mol M
2.88×10⁻³ mol M₂O₃

C

4.79×10⁻⁴ mol M
9.59×10⁻⁴ mol M₂O₃

D

2.88×10⁻³ mol M
1.44×10⁻³ mol M₂O₃

Was this helpful?

Learn this concept